Neural implant systems such as cochlear implants deliver stimulation signals to target neural tissue. For example, FIG. 1 shows a cochlear implant arrangement where an implant electrode 100 penetrates through a cochleostomy opening 102 into a patient cochlea 101. The intra-cochlear portion of the implant lead is referred to as the electrode array 103 and includes multiple stimulation contacts 104 that deliver electrical stimulation signals to auditory neural tissue within the cochlea 101.
Existing commercial neural implant systems are based on the use of electrical stimulation signals, but there have been some recent proposals to stimulate nerves either optically or optically in combination with electrical stimulation. A light source can be generated locally in the vicinity of the nerve (e.g. by LEDs or micro-lasers), or it can be generated remotely and transported to the nerve (e.g., by optical fiber).
U.S. Patent Publication 20100174329 described a proposed arrangement for combined optical and electrical neural stimulation. The general ideas of such an arrangement were broadly discussed, but specific structural details of the optical stimulation arrangement were scant. For example, only fleeting mention was made of optical adjustment structures. Each optical stimulation contact was described as a single individual light source. WO 2007013891 also described an optical stimulation arrangement for cochlear implants but again seemed to offer little specific discussion of controlling the optics beyond suggesting that it might be useful to arrange some combination of a mirror, lens or prism. Optical stimulation of nerves was also discussed in US 20060129210 and US 20100114190, but again, some structural details are sketchy or unaddressed. US2012 0197374 described an implant carrier member with optical stimulation contacts having multiple optical sub-elements to control the shape and direction of the optical stimulation field.